# Decoherence and pointer states in small antiferromagnets: A benchmark test

### Submission summary

 Authors (as Contributors): Hylke Donker
Submission information
Date accepted: 2017-02-24
Date submitted: 2017-02-17 01:00
Submitted by: Donker, Hylke
Submitted to: SciPost Physics
Ontological classification
Specialties:
• Condensed Matter Physics - Theory
• Quantum Physics
Approach: Computational

### Abstract

We study the decoherence process of a four spin-1/2 antiferromagnet that is coupled to an environment of spin-1/2 particles. The preferred basis of the antiferromagnet is discussed in two limiting cases and we identify two $\it{exact}$ pointer states. Decoherence near the two limits is examined whereby entropy is used to quantify the $\it{robustness}$ of states against environmental coupling. We find that close to the quantum measurement limit, the self-Hamiltonian of the system of interest can become dynamically relevant on macroscopic timescales. We illustrate this point by explicitly constructing a state that is more robust than (generic) states diagonal in the system-environment interaction Hamiltonian.

Published as SciPost Phys. 2, 010 (2017)

### List of changes

1) The figures have been enlarged, in particular Figs. 2 & 5.

2) The units of time t is stressed in the captions of the figures.